Known in the art are crystals and glasses of different compositions containing trivalent neodymium as active ions.
One of known compositions of phosphate glass for laser use is the composition of the following components in mol. %:
______________________________________ phosphoric anhydride 55-70 aluminium oxide 1-15 neodymium oxide 0.5-5 oxide of at least one of alkaline metals 10-25 oxide of at least one of the metals: La, 5-15 Ba, Ca, Sr, Mg (French Patent No. 2,304,582). ______________________________________
The above-cited composition is disadvantageous in that the concentration of active neodymium ions is limited to 0.01-5 mol %.
An increase in Nd.sup.3+ concentration leads to strong concentration quenching of Nd.sup.3+ luminescence and degradation of adsorbed energy to thermal vibrations, which deteriorates considerably the output characteristics of lasers. The limitation of concentration of Nd.sup.3+ ions does not allow the required optical densities to be attained in small volumes which, in its turn, restricts the degree of miniaturization of lasers.
It is an object of the Invention to eliminate the above-cited disadvantages.